Steel and plastic strapping are used for a wide variety of applications, often to secure very large coils of steel, synthetic fiber bales and heavy palletized boxes. Steel strapping has advantages in that it has high strength and temperature resistance and outstanding creep resistance. Steel strapping is typically used on heavy loads where high strap strengths and low creep properties are required. However, steel strapping, although very useful in maintaining the quality of the packaging, may be more difficult to dispose of and the strap can have sharp edges.
Plastic strap has found particular application to lower strength packaging requirements and represents a less expensive alternative to steel strap. Plastic strap typically has an elastic behavior within limits which allows the strap to remain tight on a package even if the package collapses or somewhat consolidates. The plastic strap is easily disposed of and is safer to use than steel strap because it does not have the dangerous sharp edges of steel strap.
Polypropylene has been proposed as material to be used in plastic strap in EP 115917. However this document describes a generic polypropylene homopolymer.